Tonsillitis, that is inflammation of the tonsils, is a wide-spread health problem. It is estimated that in Sweden approximately 300 000 people are affected each year by acute tonsillitis. About 30-50% of these cases are caused by .beta.-streptococci. Tonsillitis is usually treated with penicillin, e g phenoxymethyl penicillin, but in about 10-25% of the cases the treatment is ineffective, and the patient is affected by recurrent tonsillitis. Tonsillitis is particularly common at day care centers, in schools and also within families, where people are in close contact with each other and several chances of infection occur. The consequences are recurrent medical treatment, sick reportings and penicillin treatment, which are not only a great health problem but also an economical problem.
The reasons for the relatively high frequency of ineffective treatments are supposed to depend on, apart from local deficiencies in the immuno defence of the patient and general immunological deficiencies, inadequate antibiotic activity ,At the site of infection. The latter includes such factors as the compliance of the patient to the medication, the particular dosage of the penicillin, the number of doses and impaired absorption of the drug. Also inactivation of penicillin by .beta.-lactamase producing bacteria, resulting in an insufficient penicillin concentration at the focus of infection has been mentioned. Other factors connected with ineffective treatments of .beta.-streptococcal tonsillitis is disturbancies of the normal flora resulting in an increased susceptibility to streptococcal infections and penicillin tolerance of the group A .beta.-streptococci.
It is known that bacterial interference among the bacteria of the throat flora may play an important role at tonsillitis. It has been demonstrated that certain strains of streptococci inhibit the growth of ordinary infection producing .beta.-streptococci. This applies particularly to certain .alpha.-streptococci. People with the above mentioned recurrent infections are often lacking inhibiting .alpha.-streptococci in their normal throat flora, while people having these .alpha.-streptococci seldom are afflicted with tonsillitis.
Sanders et al. (Sanders, C., Nelsen, G., Sanders, E.: Bacterial interference, II. Epidemiological determinants of the antagonistic activity of the normal throat flora against group A streptococci. Infection and Imminity 1977, 16:599-603) have demonstrated that certain strains of Streptococcus viridans inhibit the growth of group A streptococci (GAS). Sanders also demonstrated an inhibiting effect of normally occurring .alpha.-streptococci against GAS in infected children.
The protective role in the throat of .alpha.-streptococci against .beta.-streptoccocal infections has also been shown by Grahn and Holm (Grahn, E., Holm, S. E.: Bacterial interference in the throat flora during a streptococcal tonsillitis outbreak in an apartment house area. Zentralblatt fe,uml/u/ r Bakteriologie Mikrobiologie und Hygiene A 1983, 256:72-79) and Roos et al. (Roos, K., Grahn, E., Holm, S. E.: Evaluations of betalactamase activity and microbial interference in treatment failures of acute streptococcal tonsilitis. Scandinavian Journal of Infectious Diseases 1986, 18:313-19). They have elucidated that the lack of interfering .alpha.-streptococci is one of the main reasons of the often ineffective treatment of streptococcal tonsillitis.
Further, Beck (Interference by an .alpha.-hemolytic streptococcus of .beta.-hemolytic pathogenic streptococci, Inflammation, 3:463-465, 1979) has found a strain of Streptococcus viridans with a high inhibiting capacity against GAS and he has suggested "implantation" of this strain in people with recurrent streptococcal tonsillitis. A similar report has previously been presented by Sprunt et al. (Sprunt K., Leidy G., Redman W.: Abnormal colonisation of neonates in an ICU: Conversion to normal colonisation by pharyngeal implantation of alpha-hemolytic streptococcus strain 215. Pediatr Res 14:308-313, 1980), who implanted a strain of .alpha.-streptococci in the nasopharynx of 22 children apprehended to be in danger of infection. The implantation turned out to be successful in 16 of the children and caused a change to the normal flora in 7 of the children to the effect that the implanted strain was the sole strain of .alpha.-streptococci to be found 4-18 days after the implantation.
The bacteria in the normal flora inhibit invading bacteria in different ways, and the factors behind are e g competition for important growth factors, pH-variations, accumulation of waste products, formation of peroxide, bacterial toxins and enzymes, and also production of substances known as bacteriocins. The known bacteriocins are very similar to antibiotics, but differ in having a very selective effect and do not disturb the very important anaerobic bacterial flora. The inhibiting effect of the .alpha.-streptococci on the .alpha.-streptococci has been shown to depend in a high degree on the presence of bacteriocins produced by .alpha.-streptococci. There exists a need for an effective pharmaceutical preparation in the prophylaxis against and treatment of .beta.-streptococcal tonsillitis.